One vertex per element, one color per generator, with an edge from x to x·s.
(10,14)(15,21)(16,22)(23,24)(25,26)(27,28)(29,37)(30,34)(31,32)(33,39)(35,40)(36,38) involution — undirected(1,2)(3,6)(4,7)(5,8)(9,10)(11,15)(12,16)(13,14)(17,23)(18,21)(19,24)(20,22)(25,27)(26,31)(28,34)(29,38)(30,32)(33,36)(35,39)(37,40) involution — undirected(1,3)(2,5)(4,8)(6,7)(25,28,30,31)(26,32,34,27)(29,36,39,40)(33,38,37,35)(9,10)(11,15)(12,16)(13,14)(17,23)(18,21)(19,24)(20,22)(25,29)(26,33)(27,35)(28,36)(30,39)(31,40)(32,38)(34,37) involution — undirected(1,3)(2,6)(4,8)(5,7)(9,11,13,18)(10,15,14,21)(12,19,20,17)(16,24,22,23)(25,27)(26,28)(29,35)(30,32)(31,34)(33,36)(37,40)(38,39)(1,2)(3,5)(4,7)(6,8)(9,12,13,20)(10,16,14,22)(11,17,18,19)(15,23,21,24)(25,26)(27,31)(28,32)(29,33)(30,34)(35,40)(36,38)(37,39)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.